Natural gas hydrates (NGHs) production has aroused wide attention in recent years. Currently, the depressurization is regarded as the most effective method for hydrate production. However, there is still exist the insufficient driving force in depressurization anaphase. In this study, two modes of depressurization combined with water-gas flow was adopted to dissociated methane hydrate (MH). The results found that the depressurization can promote hydrate dissociation at first and optimized the water-gas flow environment by increasing permeability. And the water-gas flow will provide extra dissociation driving force by accelerating heat and mass transfer and increasing chemical potential difference. What’s more, the mode of simultaneous implementation of depressurization and water-gas flow has a stronger promotion effect on hydrate production than the separate implementation of depressurization and water-gas flow.
Keywords natural gas hydrate, depressurization, water flow erosion, water-gas flow, hydrate exploitation